Energy and Resource Efficient Production of Fluoroalkenes in High Temperature Microreactors

Abstract

Tetrafluoroethylene (TFE) and hexafluoropropylene (HFP) are the most common monomers for the synthesis of fluoropolymers at industrial scale. Currently, TFE is produced via multistep pyrolysis of chlorodifluoromethane (R22), resulting in a high energy demand and high amounts of waste acids, mainly HCl and HF. In this study, a new chlorine-free process for producing TFE and HFP in a microreactor is presented, starting from partially fluorinated alkanes obtained from electrochemical fluorination (ECF). In the microreactor, high conversion rates of CHF3, which is used as a surrogate of partly fluorinated ECF streams, and high yields of fluoromonomers could be achieved. The energy saving and the environmental impact are shown by a life cycle assessment (LCA). The LCA confirms that the developed process has economical as well as ecological benefits, and is thus an interesting option for future industrial production of fluoroalkenes.

Global emissions of perfluorocyclobutane (PFC-318, <i>c</i>-C<sub>4</sub>F<sub>8</sub>) resulting from the use of hydrochlorofluorocarbon-22 (HCFC-22) feedstock to produce polytetrafluoroethylene (PTFE) and related fluorochemicals

“…Historically, similar c-C 4 F 8 byproduct venting occurred in the US and Europe (Mühle et al, 2019), unnecessarily increasing the carbon footprint of this industry. Note that Ebnesajjad (2015) and e.g., Mierdel et al (2019) discuss research into the use of refined methods of electrochemical fluorination (ECF) and waste recycling which may offer significantly reduced by-product formation rates in addition to energy savings and overall waste reduction.…”

Fluorinated Pyridine Aryl Ether Polymers with Defined Microstructures, Diverse Architectures, and Tunable Thermal Properties

“…4,4′-((Propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis (2,3,5,6tetrafluoropyridine) (TFP BPA). Cesium carbonate (46.4 g, 131.4 mmol), pentafluoropyridine (22.2 g, 131.4 mmol), and 4,4′-(propane-2,2-diyl)diphenol (10.0 g, 43.8 mmol) were combined in acetonitrile (250 mL) and stirred for 24 h at room temperature.…”

“…2−4 As of this writing, the worldwide increase in the production of fluoropolymers continues, as breakthroughs in advanced technologies are often achieved by their desired properties over hydrocarbon polymer analogues. 5 While chain-growth perfluorinated homopolymers such as poly(tetrafluoroethylene) (PTFE), poly(vinylenedifluoride) (PVDF), and copolymer combinations thereof dominate the global supply of thermoplastics and elastomers, 6 fluorinated aromatic polymers have resided as academic curiosities for niche applications. Vinyl fluoropolymers suffer from many limitations.…”

“…While chain-growth perfluorinated homopolymers such as poly­(tetrafluoroethylene) (PTFE), poly­(vinylenedifluoride) (PVDF), and copolymer combinations thereof dominate the global supply of thermoplastics and elastomers, fluorinated aromatic polymers have resided as academic curiosities for niche applications. Vinyl fluoropolymers suffer from many limitations.…”

Global Emissions of Perfluorocyclobutane (PFC-318, c-C<sub>4</sub>F<sub>8</sub>) Resulting from the Use of Hydrochlorofluorocarbon-22 (HCFC-22) Feedstock to Produce Polytetrafluoroethylene (PTFE) and related Fluorochemicals

“…Note that Ebnesajjad (2015) and e.g. Mierdel et al (2019) discuss research into the use of electrochemical fluorination (ECF) which may offer significantly reduced by-product formation rates in addition to energy savings and overall waste reduction.…”